Skylight structures of various types are known in residential and commercial construction. Such structures have transparent or translucent glass and/or plastic lenses which admit outside light through an opening in a roof or ceiling into an underlying space. The skylight may provide useful illumination, or merely serve a decorative or aesthetic purpose.
There are times when it is desirable to be able to temporarily block the transmission of light through a skylight. This may occur, for example, in tropical climes, when it is sought to cover the skylight in order to avoid the adverse effects of intense heat or glare radiated through the skylight when the sun is directly overhead, or when somebody who works nights is trying to sleep in an underlying bedroom. This may also occur at night, to prevent outsiders from being able to see through the skylight into the privacy of an artificially illuminated area below.
Conventional skylight covers take the form of flexible curtains or mats that are drawn, typically by edge-connected cords or webbing, across the skylight lenses or openings. The flexible nature of such covers makes them difficult to clean and often leads to snagging and other problems associated with their usual drawstring operation. The mechanisms used to drive such covers constitute separate elements independently mounted on the skylight or adjacent structures and, so that they are hidden from view, are frequently located in places that are difficult to access for servicing. Moreover, the flexible covers serve little, if any, back up to shield against debris should the skylight break because of a violent storm, or otherwise. Examples of prior art skylight shades are given in U.S. Pat. Nos. 4,665,964; 4,762,160 and 5,088,543.